Wednesday, October 5, 2016

CNR-IMM Italy employes Sentech SI PEALD LL for new high-k materials

SENTECH Instruments GmbH of Berlin, Germany says that the Institute for Microelectronics and Microsystems (CNR-IMM) in Catania – which is part of the Physics and Matter Technologies Department (DSFTM) of the National Research Council of Italy (CNR) - is using an SI PEALD LL plasma-enhanced atomic layer deposition tool with an 8-inch wafer configuration to investigate the integration of novel high-k gate dielectrics and passivating layers on devices based on gallium nitride (GaN) and other wide-bandgap semiconductors. 


The picture above shows the SI PEALD LL in the CNR-IMM cleanroom. (picture released by Sentech)

SENTECH says that its proprietary true remote CCP (capacitively coupled plasma) source is especially suited to such low-temperature and no-damage applications. The special design of the plasma source allows only radicals to reach the wafer surface, whereas high-energy photons and ions are completely blocked.

In conjunction, IMM and SENTECH have signed a joint development agreement (JDA) with the aim of the developing and characterizing laminated layers. The use of alternative high-k materials enables the shrinking of devices while maintaining their capacitance and reducing the leakage current density. In particular, the growth of Al2O3-HfO2 laminated layers is among the most often used combinations for such applications.



"The SENTECH SI PEALD LL reactor is a high-performance and flexible system, allowing the production of several high-quality dielectric thin films, whose physical properties can be tailored upon changing their chemical composition," says Dr Raffaella Lo Nigro, who is the scientist in charge of the SI PEALD LL tool and of cooperation with SENTECH. Nigro has wide-ranging expertise in the synthesis of binary and complex thin films by chemical vapor deposition (CVD) methods for several microelectronic applications. "Possible applications of this activity are related not only to the integration of novel gate dielectrics and passivating layers on wide-bandgap semiconductors but also for RF devices based on graphene," he adds.

The results of this work have already been published in scientific papers (Raffaella Lo Nigro, Emanuela Schilirò, Giuseppe Greco, Patrick Fiorenza and Fabrizio Roccaforte, Thin Solid Films, vol601, 2016, p68-72). Nanolaminated Al2O3-HfO2 and Al2O3/HfO2 bilayer thin films have been grown by PEALD on silicon substrates. Morphological, crystalline and electrical properties of the layer stacks were analyzed after low-temperature deposition and high thermal treatment. The highly stable deposition of single films and multi-layer laminates using SENTECH PEALD together with very good uniformity of the deposition process over the whole wafer are essential prerequisites for applications such as designing new high-k dielectrics, says the firm.